Containers for pourable substances, such as juices, milk, etc. commonly include a pouring spout, commonly called a fitment in the industry, which is associated with the top end of the container. Desirably, such pour spout is mounted in covering relationship to an opening defined through the thickness of the top end of the container, includes a tamper evident component and a cap for selectively reclosing the spout for storage of contents remaining in the container.
Paperboard is a common material used in the manufacture of containers for pourable substances. Closures for the top end of many paperboard containers include the well-known gable top type end closure wherein the top end of the container includes at least two flat panels which rise at acute angles toward each other from opposite side panels of the container and have their distal edges joined together in the form of a fin which extends across the width of the container.
Heretofore it has been common to define an opening through one of the top flat panels and mount a pour spout in covering relationship to the opening to define a conduit through which the contents of the container may be poured from the container.
Desirably, the fitment is also provided with a tamper evident component.
U.S. Pat. Nos. 5,133,486; 5,735,426 and 6,390,342 disclose fitments which include an integrally formed tear-away membrane which seals a conduit defined by the fitment until the membrane is pulled away, as by a finger ring, to initially open the conduit for the flow of the container contents therethrough. This tear-away membrane provides tamper evident protection for the contents of the container. Further, caps used to reclose the conduit for storage of unused contents of the container are disclosed in these patents. These fitments are of the two-piece variety in that the cap is neither integrally formed with nor otherwise attached to the fitment or container.
U.S. Pat. Nos. 3,135,441; 3,239,112; 3,458,080. and 4,022,357 disclose fitments of a one-piece variety wherein the reclosable cap of the fitment is integral with the fitment. These fitments are of the one-piece variety.
All known fitments of the prior art employ a true circular opening defined through the wall thickness of the container, usually through a panel which is a part of the top end closure of the container. Further, the known prior art fitments define a true cylindrical conduit for the discharge of the contents of the container. Such conduit establishes a flow path of a finite length along which the contents of the container must flow as they exit the container. This flow path further provides the only path for the entry of ambient air into the container to replace the outgoing volume of pourable substance and thereby avoid the development of a vacuum within the container as the outpouring of contents proceeds. Most commonly when the contents of the container are being discharged through the conduit, the outgoing substance, commonly a liquid, fully fills the conduit and blocks the inflow of replacement air until such time as the vacuum developed inside the container overcomes the outflow of contents. Thereupon, there is a sudden rush of air into the container and a concomitant dramatic fluctuation in the rate of outflow of the container contents. This action is likened to a burp and dramatically disrupts the desired continuity of the outflow of the contents from the container. Much splatter of the contents may occur and/or spillage of the contents outside a receptacle provided for the receipt of the outflowing contents. One effort to avoid this undesirable situation has been to insert a separate air intake tube leading from outside to the interior of the container. Manufacture of fitments with such tubes is difficult and costly. Further, placement of the inboard end of the tube such that the tube itself does not become filled with contents from the container, and thereby fail as an air intake to the container, has not successfully been solved in the prior art. In some instances, the rate of discharge of the contents from the container greatly exceeds the flow capacity of the air infeed tube, thereby defeating the purpose of the tube. Larger tubes detract from the area of the conduit exit through which the contents of the container can flow, thereby causing the outflow of the contents to be undesirably slow.